Study of dosimetric and spatial variations due to applicator positioning during inter-fraction high dose rate brachytherapy in the treatment of carcinoma of the cervix; A three dimensional dosimetric analysis

Background: This study evaluates dosimetric and spatial variations in inter-fraction applicator positioning in high dose rate [HDR] brachytherapy

Materials and Methods: This study includes 25 retrospective patients of carcinoma of the cervix. Each patient received 5 fractions of HDR intracavitary brachytherapy. High Risk-Clinical Target Volume [HR-CTV] were drawn on CT images. First implant was considered as a reference, and all subsequent CT data sets were rigidly registered on first implant's CT data set. Another point A, called point Aabs, was defined on first plan and all subsequent plans. Registration properties were recorded for all 125 plans that include X, Y, Z DICOM offset, rotational, translational values and normalized D90 [ND90] doses were also recorded

Results: The mean angle of rotation on X, Y and Z axis are 0.63 +/- 1.85 deg, -0.86 +/- 1.30 deg, -1.14 +/- 2.44 deg, respectively. While mean translational motion on X, Y and Z axes are -2.77 +/- 10.32 mm, -6.12 +/- 9.71 mm and 14.62 +/-23.83 mm, respectively. Mean ND90, and mean HR-CTV were found to be 1.18 +/- 0.26 and 26.91 +/- 17.70 cc, respectively

Conclusion: Results of the study reveals that translational motion is higher than the rotational motions, and inter - fraction applicator variation does not produce any significant change in Point A doses. The change in volume coverage is observed only due to applicator motion. HR-CTV coverage decreases with increasing HR-CTV volume. Hence, dose prescription should be based on 3D HR-CTV volume?

Antiviral activity of ecasol against feline calicivirus, a surrogate of human norovirus

Human norovirus [NoV] is a major cause of acute gastroenteritis in closed settings such as hospitals, hotels and cruise ships. The virus survives on inanimate surfaces for extended periods of time, and environmental contamination has been implicated in its transmission. The disinfection of contaminated areas is important in controlling the spread of NoV infections. Neutral solutions of electrochemically activated [ECA]-anolyte have been shown to be powerful disinfectants against a broad range of bacterial pathogens. The active chemical ingredient is hypochlorous acid [HOCl], which is registered as an approved food contact surface sanitizer in the United States by the Environmental Protection Agency, pursuant to 40 CFR 180.940. We evaluated the antiviral activity of Ecasol [an ECA-anolyte] against feline calicivirus [FCV], a surrogate of NoV. FCV dried on plastic surfaces was exposed to Ecasol for 1, 2, or 5 min. After exposure to Ecasol, the virus titers were compared with untreated controls to determine the virus inactivation efficacy after different contact times. Ecasol was found to decrease the FCV titer by >5 log[10] within 1 min of contact, indicating its suitability for inactivation of NoV on surfaces

Human catalase: looking for complete identity

Catalases are well studied enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide. The ubiquity of the enzyme and the availability of substrates made heme catalases the focus of many biochemical and molecular biology studies over 100 years. In human, this has been implicated in various physiological and pathological conditions. Advancement in proteomics revealed many of novel and previously unknown features of this mysterious enzyme, but some functional aspects are yet to be explained. Along with discussion on future research area, this mini-review compile the information available on the structure, function and mechanism of action of human catalase.

A Serine12Stop mutation in PB1-F2 of the 2009 pandemic (H1N1) influenza A: a possible reason for its enhanced transmission and pathogenicity to humans

As the scientific community scrambles to define the ancestry and lineages of the eight segments of new pandemic H1N1 strain, we looked for unique genetic events in this virus's genome to explain the newly found enhanced virulence and transmissibility among humans. Genome annotations of this virus identified a stop mutation replacing serine at codon 12 (S12Stop) of the PB1-F2 protein, a virulence factor in influenza A viruses. Here, we discuss the significance of this finding and how it may contribute to host specialization, explaining the virtual absence of the H1N1 influenza A virus strain in pig populations. This finding is expected to lead to a better understanding of the transmission and pathogenesis of the 2009 pandemic strain.

Helicobacter pylori, effect of its eradication on serum gastrin in gastritis and duodenal ulcer patients

It was observed that hypergastrinemia occurs with Helicobacter pylori [H. pylori] infection whether it may play a role in the pathogensis of duodenal ulcer disease or not, still controversial, Aim of the study is to observe the effect of H. pylori infection among duodenal ulcer [DU] and chronic gastritis patients before and after H. pylori eradication and observe the changes in serum gastrin levels and the reflection on the pathological course of gastritis and DU. disease. Out of 380 chronic dyspeptic patients 154 patients were H. pylori positive [40.5%]. DU was detected in 17.5% of H. pylori positive and in 8.8% with H. pylori negative dyspeptic patients. Serum fasting gastrin levels were measured by standard radioimmunoassay techniques, in 45 DU patients [25 patients of them were H. pylori infected] and 40 chronic gastritis patients [20 patients were H. pylori infected] before and one month after H. pylori eradication. In addition to a control group included 15 normal H. pylori negative individuals. H. pylori detection and monitoring was assessed by serologic test [ELISA], bacteriological culture, Clo test [unease test] and histopathological examination [Giemsa stain] before and after therapy. Colloidal bismuth, amoxicillin and metronidazole triple therapy was used for H. pylori eradication. Fasting hypergastrinemia was detected significantly among DU and chronic gastritis H. pylori infected patients [P<0.001], than H. pylori negative comparable groups and normal controls. Reversed hypergastninemia [mean values] were observed significantly [P<0.01], among chronic gastritis and DU, H. pylori infected groups after a month of triple therapy for H. pylori eradication. Successful eradication was achieved in 75% and 88% as detected by ELISA technique, 100% by bacterial culture, 90% and 88% by Clo test and 100% to 92% by histopathological examination among chronic gastritis and DU groups respectively. Although, significant decrease in the mean values of fasting serum gastrin after H. pylori eradication in chronic gastritis patients [P<0.01], the improvement in the grades of gastritis showed insignificant changes [P>0.05]. Also, a significant decrease in the fasting serum gastrin mean values in DU H. pylori infected patients after a month of H. pylori eradication [P<0.01], however, non significant differences were reported between the rates of complete DU healing, partial healing and non healing ulcers among H. pylori negative or positive DU groups [P>0.05]. In These findings suggest that hypergastrinemia is secondary to H. pylori infection and related to mucosal inflammation and play a minor role in inducing duodenal ulcer disease. Although, ELISA test is the most sensitive for H. pylori detection but its reliability in assessing eradication needs a further study. Also, serum gastrin measurement can be used to assess H. pylori eradication